Expression analysis of Barrett's esophagus-associated high-grade dysplasia in laser capture microdissected archival tissue.
OBJECTIVE
Identifying genes differentially expressed in nondysplastic BE (NDBE) from those expressed in high-grade dysplasia (HGD) should be of value in improving our understanding of this transition and may yield new diagnostic and/or prognostic markers. The aim of this study was to determine the differential transcriptome of HGD compared with NDBE through gene microarray analysis of epithelial cells microdissected from archival tissue specimens.


METHODS
Laser capture microdissection was used to isolate epithelial cells from adjacent inflammatory and stromal cells. Epithelial mRNA was extracted from areas of NDBE and HGD in matched biopsies from 11 patients. mRNA was reverse transcribed and applied on Affymetrix cDNA microarray chips customized for formalin-exposed tissue. For a subset of these genes, differential gene expression was confirmed by real-time PCR and immunohistochemistry.


RESULTS
There were 131 genes overexpressed by at least 2.5-fold in HGD versus NDBE and 16 genes that were underexpressed by at least 2.5-fold. Among the overexpressed genes are several previously shown to be increased in the neoplastic progression of BE, as well as novel genes such as lipocalin-2, S100A9, matrix metallopeptidase 12, secernin 1, and topoisomerase IIalpha. Genes decreased in dysplastic epithelium include MUC5AC, trefoil factor 1 (TFF1), meprin A, and CD13. Real-time PCR validated the changes in expression in 24 of 28 selected genes. Immunohistochemistry confirmed increased protein expression for topoisomerase IIalpha, S100A9, and lipocalin-2 and decreased expression of TFF1 across the spectrum of BE-associated dysplasia from NDBE through adenocarcinoma.


CONCLUSIONS
This is the first study to identify epithelial genes differentially expressed in HGD versus NDBE in matched patient samples. The genes identified include several previously implicated in the pathogenesis of BE-associated dysplasia and new candidates for further investigation.
Sabo
Edmond
E
Department of Pathology and Medicine, Rhode Island Hospital, Providence, Rhode Island 02903, USA.
Meitner
Patricia A
PA
Tavares
Rosemarie
R
Corless
Christopher L
CL
Lauwers
Gregory Y
GY
Moss
Steven F
SF
Resnick
Murray B
MB
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001471:Barrett Esophagus / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004947:Esophagus / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D007834:Lasers; D042282:Microdissection; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D012334:RNA, Neoplasm